At the present time, electronic timepieces are in widespread use, and there is an increasing demand for increased accuracy of timekeeping by such timepieces. At the same time, as electronic wristwatches are made smaller in size, there is a requirement for minimum power consumption, so as to extend the operating lifetime of the timepiece battery as far as possible, or to use a smaller size of battery. One method of achieving high accuracy of timekeeping is to utilized a standard frequency timebase signal source consisting of a quartz crystal oscillator circuit incorporating an AT-cut quartz crystal vibrator operating at a very high frequency, for example of the order of 4 MHz. However, the use of such a high timebase signal frequency brings disadvantages in the form of increased power consumption. The high frequency crystal oscillator circuit itself consumes a significantly greater level of power than a lower frequency oscillator, and also the power consumed by a frequency divider which receives the high frequency signal is substantially increased as compared with the case of a lower frequency of timebase oscillator. The use of a high value of timebase signal frequency provided by a quartz crystal oscillator circuit is therefore not compatible with the requirement for a low level of power consumption, if the conventional method of direct frequency division of the high frequency signal is utilized. For this reason, the timebase signal of an electronic timepiece is generally provided by a quartz crystal oscillator circuit operating at the order of 32 KHz, since reduction of battery power consumption as far as possible is en extremely important consideration in electronic timepiece design.
These disadvantages of the prior art are avoided by the present invention, whereby a relatively low frequency signal of only moderate frequency stability serves to produce a signal which is frequency-processed to provide a timebase signal which is (when averaged over a certain minimum period of time) an exact integral submultiple of the frequency of a high-stability quartz crystal oscillator circuit. Since direct frequency division of the output signal from the high frequency oscillator is not performed, the disadvantages of increased power consumption referred to above are avoided. In addition, the high frequency oscillator is activated only periodically, with a very low duty cycle, so that only a very low level of power is consumed by it.